Fan or blower for fuel burners



April 24, 1934. E J, LATTNER 1,955,852

FAN OR BLOWER FOR FUEL BURNERS Filed No v. 21. 1932 INVENTOR. f/7 E7jZflTf/VEE 7 V BY I ATTORNEY. I

Patented Apr. 24, 192.4

UNITED STATES PATENT? OFFICE FAN on BLOWER FOR FUEL. BURNERS Emert J.Lattner, Cedar Rapids, Iowa Application November 21, 1932, SerialNo.643,560

' 3 Claims. (01. 230-114) This invention relates tofluid fuel burnersand particularly to that type of burner in which liquid or gaseous fuelunder pressure is atomized and mixed with a blast of air delivered intothe furnace by suitable air circulating means.

In burners of the type referred to, the fuel and air are mixed byejecting the fuel under pressure from a nozzle usually enclosed withina: tube or conduit through which air at a fairly high velocity isdelivered. The air with which the fuel is mixed is usually drawn intothe rear end of the tube or conduit by means of a fan or blower locatedin the conduit and then delivered out of the conduit by means of thefan. The fuel is usually delivered to the nozzle by means of a pumpdriven by the same motor which drives the fan.

It is very essential for proper and efficient operation of the burnerthat means be provided for controlling the relative amount of air inproportion to fuel at all speeds of the fan. If the proportion of airandfuel is not correct the mixture is too lean or too rich andcombustion is incomplete and inefllcient.

The air flow control means must be adjustable to permit its adjustmentto secure the correct volume of air in relation to the volume of fuel,and means should be provided for locking the air flow control means inthe preferred position. The air flow control means must be simple andinexpensive in construction and must be built into the burner, and in apreferred construction is arranged so that fuel flow control devices maybe supported by the air flow control means. It is also desirable thatthe air flow control means should break up the air stream as much. aspossible and cause it to eddy and swirl to promote mixing of the fueland, air. The air flow control .means must also be so arranged as tominimize any sound the air may make in flowing into and out of theconduit.

I'have accordingly devised an air flow control means which meets theproblems above mentioned and overcomes the difliculties of the devicesof the prior art.

A general object of my invention is to provide an air flow control meansfor fuel burners.

A more specific object of my invention is to provide an air flow controldevice for fuel burners which may be adjusted to regulate the quantityof air admitted to the burner, and to properly'proportion the volume ofair admitted to the volume of fuel delivered by the nozzle of theburner.

Another object of my invention is to provide a simple and inexpensiveair flow control means which is a built-in part of the burner and whichmay be utilized as a mounting for other parts of the burner.

Another object of my invention is to provide an air flow control andmixing means which will promote proper mixing of the fuel and air andwhich will minimize or eliminate sounds made by the air as it rushesthrough the burner.

Other and further features and objects of the invention will be moreapparent to those skilled 86 in the art upon a consideration of theaccompanying drawing and following specification, wherein is disclosedan exemplary embodiment of the invention, with the understanding,however, that such changes may be made therein as fall within the scopeof the appended claims without departing from the spirit of theinvention. The device may be used or adapted for use for other purposes.

In the drawing:

Figure 1 is a view in right side elevation of 91 fuel burner having as apart thereof an air flow control means constructed according to oneembodiment of my invention. Portions of the structure have been brokenaway to show the remaining parts in greater detail.

Figure 2 is a view in perspective of the coupling flange of a pump whichis adapted to be mounted upon one of the members of the air flow controlmeans.

Figure 3 is a view in perspective of one of the members of the air flowcontrol means constructed according to my invention.

Figure 4 is a view in perspective of another member of the air flowcontrol means.

Figure 5 is a view in perspective showing the portion of the conduit towhich the air flow control member shown in Figure 3 is secured. Figures2, 3, 4 and 5 show the respective parts in exploded relation, and

Figure 6 is a view in perspective of the locking means used for lockingthe air flow control means in position when proper adjustment of theparts thereof has been secured.

Referring now to the drawing and more par- 100 ticularly to Figure 1,the burner structure as a whole is mounted upon a base 10 which may besecured to the floor or other suitable foundation by means of bolts 11.A standard 12 projects vertically from the base 10 and affords a means105 whereby the fan housing 13, which acts also as a main frame member,may be mounted upon the base.

The box-like housing 13 is provided with a clamping bracket member 14 atthe rear wall 110 thereof for clamping the housing 13 to the standard 12at any suitable distance from the floor.

A driving motor (not shown) of any usual construction is preferablybolted to the left side of the housing and the shaft of the motorprojects into the housing 13, and a fan, indicated at 20, for drawingair into the housing 13 and driving it through the blast conduit 26, ismounted on the end of the shaft. The rotating parts of the fuel pump 31are also driven by the same motor which drives the fan and suitableconnections are employed for driving the fan and pump from the motor. Inthe present instance any suitable motor, fan and fuel pump may beemployed, and therefor these parts need not be further described.

It is very desirable that the axis of the fan be located below thecenter-line of the blast conduit 26 in order to lower the center ofgravity of the mass of the burner, and in order that the fuel flowcontrol devices mountedon the righthand side of the housing 13 will belocated below the nozzle 25 and nozzle feed pipe 27, so that when theburner is stopped, .fuel within the feed pipe 27 immediately drains backinto the fuel feed control means. This construction and location ofparts is novel in the fuel burner art and is of considerable importancebecause the fuel flow control devices afford chambers into which fuelwithin the upper portion of the feed pipe 27 and nozzle 25 may, drainback away from the nozzle as soon as the oil burner is shut down,thereby preventing burning and smoking of the oil which would normallybe present in the feed pipe and nozzle and would drip from the nozzleafter the burner has been shut off.

Ignition of the mixture of fuel and air may be secured in any suitablemanner but in the present instance is secured by means of a transformer17 energized by the same source of electrical energy which energizes themotor previously mentioned. The transformer furnishes high potentialcurrent for the ignition points 18 by means of cable 19.

A large circular opening 30 is provided in the right-hand side of thehousing13 and the opening is covered by means of an end bell 33 ,havingradially slotted openings 34 to permit air to pass through the end bell,into the housing 13 and out through the blast conduit 26. The

direction the air takes in passing through the burner is indicated bythe small arrows. The end bell is provided with a large radiallyextending flange 35 having lugs 36 spaced about its periphery in orderthat the end bell may be secured to the face of the housing 13 over thecircular opening 30 as'by means of bolts 38.

The greater part of the end bell is comprised of curved triangularportions or louver strips 39 having their apexes connected by acylindrical flange 41 and connected at their bases by the flange 35. Thestrips are spaced apart to provide the triangular openings or louvers 34beforementioned. The cylindrical flange 41 is provided with tappedradial openings 42 in order that the cylindrical portion 37 of the pump31 may be placed in the opening within the flange and clamped by meansof set screws threaded into the tapped openings 42. The cylindricalportion 37 of the pump 31 projects through the cylindrical flange 41 andbeyond the inner wall thereof. A lug 43 projects downwardly from thecylindrical flange or ring 41 and the lug is provided with an axiallyextending opening 44 in which a thumb screw 46 may be placed ashereinafter,

described.

A second bell-shaped member or shutter 61 is provided and this member isof substantially the same construction as the member 33 shown in Figure3 except that the flanges 35 and 41 are not used but the inner ends ofthe louver strips 62 are connected by means of a circular webbed portion63 and the outer ends by means of another webbed ring-like portion 64.The circular webbed portion 63 of shutter 61 fits over the inwardlyprojecting flange 37 of pump 31 and is rotatably supported thereby. Theopenings or louvers 66 are triangular and of substantially the sameshape and area as the openings 34 in the end bell 33. The shutter 61' isof smaller diameter than the end bell 33 and its axial dimensions areless, so that the shutter nests in the end bell.

A lug 67 projects axially from one side of the lowermost of .the louverstrips 62, and when the shutter is in place in the end bell, the lug 67projects out through the lowermost louver 34a in the end bell 33 so thatit may be moved to rotate the shutter 61 within the end bell 33. .Asuitable indentation 68 is provided in the louver 39a of the end bell sothat the lug 67 may move into the indentation to permit complete openingand closing of the louvers 34 of the end bell by the louver strips 62 ofthe shutter. The openings 66a and 66b of the shutter are slightlyshorter than the other openings 66 so that the flange 63 is enlarged atthe bottom of the central opening. A slot 71 is provided in this portionof the flange 63 and this slot is curved in a sector of a circle thecenter of curvature of which is at the axial center of the end bell 61.

The screw 46 is enlarged at the inner end of the shank to provide asquared portion 72 adapted to flt in the slot 71 and a button-likeportion 73 adapted to bear against the inner wall of the shutter 61adjacent the slot 71. The threaded shank of the screw projects throughthe opening 71 of the end bell 61 and through the opening 44 in the ring41, and a wing nut 76 having a long shank 77 is threaded on the screw 46with the inner end of the shank 77 bearing against the lug 43. It isapparent that when the thumb nut 76 is tightened on the screw 46, theshutter 61 is clamped in place within the end bell 33, but that when thewing nut 76 is loosened, the shutter 61 may be rotated by means of thelug 67 within the end bell 33 to a degree determined by the width of theopening 34a. It is apparent also that since the louver strips 62 are ofsuch a width as to overlap the openings 34 in the end bell 33, that theshutter 61 may be rotated from a position in which the louver strips 62offer no resistance to the passage of air through the end bell andshutter to a position such that the louver strips 62 entirely cover theopenings 34 in the end bell 33. The shutter 61, of course, may belocated at any position between these two extreme positions, and thusaccurately control the area of the air passageways through the end belland shutter.

The ring-like flange 41 on end bell 33 affords a means by which the pump31 may be supported on the end bell and the pump 31 is provided withsuitable flanges in order that a strainer'48 and a fuel flow controlvalve 57 may be fastened on the pump.

In operation with the burner located so that the conduit 26 projectsinto a furnace, the burner is started up and the position of the shutter61 within the end bell 33 changed until the flame within the furnaceburns with a blue color which indicates that complete and emcientcombustion is being secured. The thumb nut 76 is then tightened on thethumb screw 48 and the shutter 61 is then looked in place with relationto the end bell33.

The plurality of triangular openings of the shutter and end bell causethe air being admitted to the conduit to swirl and eddy and thus promotebetter mixing of fuel and air, and the swirling action and battle eflectoi the louver strips acts to muiile sounds emanating from within theconduit.

Although this invention has been described in connection with a certainspecific embodiment, the principles involved are susceptible of numerousother applications that will readily occur to persons skilled in theart. The invention is therefore to be limited only as indicated by thescope of the appended claims.

Is claim as my invention:

1. In a liquid fuel burner. a blast conduit, air propelling meanslocated in the rear portion of the blast conduit, and 'air flow controlmeans comprising an end bell located on the side of the blast conduitadjacent the air propelling means, the end bell having a shutter locatedwithin the end bell and means for adjusting and locking the shutter withrespect to the end bell.

2. In a fluid iuel burner, a blast conduit, air propelling means locatedin the blast conduit, and means to control the volume oi air admitted tothe conduit comprising an end hell on the side a of the conduit having aplurality of openings therethrough through which the air is admitted tothe conduit, and a bell-like shutter nested within the end bell, theshutter having a plurality of louver strips and louvers through whichthe air may pass, the shutter being adapted for rotation within the endbell to regulate the area of the openings through the end bell andshutter.

3. In a fluid fuel burner, a blast conduit, air propelling means locatedin the blast conduit, and means to control the volume of air admitted tothe conduit comprising an end bell on the side of the conduit having aplurality of openings therethrough to permit air to enter into theconduit, a shutter nested within the end bell having aplurality ofopenings corresponding to the openings in the end bell, the shutterhaving a projection adapted to project through one of the openings inthe end bell and the shutter being rotatable within the end bell bymeans of the projection whereby the shutter may be rotated from outsidethe end bell to regulate the area of the openings through the air flowcontrol means.

EMERT J. LA'I'INER.

